Meat tenderness and muscle growth: is there any relationship?

Abstract

Our objectives for this manuscript are to review the mechanisms of muscle growth, the biological basis of meat tenderness, and the relationship between these two processes. Muscle growth is determined by hyperplasia and hypertrophy. Muscle cell size is determined by the balance between the amount of muscle protein synthesized and the amount of muscle protein degraded. Current evidence suggests that the calpain proteolytic system is a major regulator of muscle protein degradation. Sarcomere length, connective tissue content, and proteolysis of myofibrils and associated proteins account for most, if not all, of the explainable variation in tenderness of meat after postmortem storage. The relative contribution of each of the above components is muscle dependent. The calpain proteolytic system is a key regulator of postmortem proteolysis. While changes in muscle protein degradation affect meat tenderization/tenderness, changes in muscle protein synthesis are not expected to affect meat tenderization/tenderness. Published by Elsevier Science Ltd.

Production and processing studies on calpain-system gene markers for beef tenderness: Consumer assessments of eating quality1

“…The calpain-calpastatin system regulates protein degradation in animals premortem and postmortem (Koohmaraie et al, 2002). The 4 markers were SNP within genes controlling the calpain-proteolytic system, specifi cally calpastatin (CAST; Barendse, 2002), calpain 3 (CAPN3; Barendse et al, 2008), and μ-calpain 1 (CAPN1-4751 and CAPN1-316; White et al, 2005 andPage et al, 2002, respectively).…”

“…Consumers consistently rate tenderness as the most important contributor to beef palatability in Australia (Egan et al, 2001) and the United States (Koohmaraie et al, 2002). Favorable genetic markers have been shown to improve shear and compression force measurements of tenderness (Cafe et al, 2010b).…”

Effects of hormonal growth promotants (HGP) on growth, carcass characteristics, the palatability of different muscles in the beef carcass and their interaction with aging

“…In reviewing the interaction between protein turnover and eating quality, Koohmaraie et al (2002) proposed that if in part an increase in net protein in the live animal was achieved by a decrease in protein turnover (i.e. as a function of increased calpastatin activity in the muscle), this would reduce post-mortem aging rates, resulting in tougher meat.…”

Effect of hormonal growth promotants on palatability and carcass traits of various muscles from steer and heifer carcasses from a Bos indicus - Bos taurus composite cross

“…In experiment 1, the balanced numbers of samples for most muscles aged 7 and 21 days showed that aging rates varied between the different muscles. Koohmaraie et al (2002) proposed that the major contributors to variation in tenderness within a muscle included the rate of proteolysis, sarcomere length and connective tissue. Increased sarcomere length impacts aging rates by causing an initial increase in tenderness with slower subsequent ageing, so that ultimately tenderness scores in stretched and unstretched muscle converge (Tornberg 1996).…”